Even though we are only a little way into the 21st century, the signs of global warming are obvious and many. There are droughts in East Africa, stranded polar bears in the Arctic, bleached coral reefs in the tropics, and retreating glaciers on land.

But the latest sign was a real surprise to me. By burning huge quantities of fossil fuels, we humans have actually tipped the Earth off its axis — by a tiny amount.

When I say “tiny”, let me emphasise how tiny. It’s centimetres per year, not hundreds or thousands of kilometres each year….

….rapid melting of ice on land has driven Earth’s North Pole to the east. This solid ice used to be on land, but is now liquid water spread everywhere across the planet.

The burning of fossil fuels by us these past few centuries has been sufficient to shift the Earth’s axis.